This Core provides scientific and state of the art technical expertise for histologic and cytologic analyses. Thus, the Core provides a wide range of histopathologic services so that pathophysiologic investigations can be substantiated with morphologic data. The Core has been used in the past and will continue to be used by all four project leaders for routine histology, immunohistochemistry, morphometry, fluorescence microscopy, image analysis and printing. The core is especially important to projects 1 and 3. Financial support for the Core arises from investigator initiated research grants and so it is a shared resource with staff support based on the needs of the individual investigators. The Core has provided partial support for this Program Project since 1986. Dr. Dannenberg, the director of the Core, adequately addressed the two criticisms associated with the initial proposal. In response to the criticism that there was little technical information provided making it difficult to assess the scientific merit of the Core, Dr. Dannenberg referred to the recent publications by the project leaders as support for the scientific merit of the Core. The second criticism concerned the prioritizing of projects. There was some concern that reduced services would result because the Core operates on a first come/first serve basis. Dr. Dannenberg points out that the problem has been less with equipment availability than with access to labor. To rectify this the Core has requested support for a technician and some additional equipment.